These look brilliant....but I can never find anywhere that sells them in my sizeI have started using A brand of inner tube called GAADI. They are a long single tube and sealed at both ends. So not a continuous loop !
This means you can put them on to a wheel without needing to get in between the wheel and rear frame. All you need to do is take off one side of the tyre, fit the tube and that's it.
Halfords do them for about a tenner. I've used them on my old Kudos King and more recently on my Oxygen CTB. Love them and although they cost a bit more, well worth it in my view. A tenner for s bike that costs 1-1.5 k isn't expensive.
I also keep a can of tyre repair foam in my panniers in case I need it.